In a hybrid electric vehicle or an electric vehicle, a battery is mounted as a drive source for an electric motor. A battery generates heat when the battery charges or discharges, and the efficiency of the battery is reduced when the battery is heated to a high temperature. Owing to this, various cooling constructions have been proposed to introduce cooling air to cool the battery (refer to Patent Literatures 1, 2, and 3, for example). On the other hand, in recent years, it has been studied that a battery and a cooling fan are integrated into a unit to be disposed within a passenger compartment, so that cooling air that has been used to cool the battery is discharged into the passenger compartment.
Patent Literature 1 discloses a power supply unit which includes a long air discharge duct which is formed to extend towards a circumferential edge portion of a passenger compartment to discharge part of air used to cool a DC-DC converter towards the circumferential edge portion, and a short air discharge duct which is formed to have a discharge line which is shorter than that of the long discharge duct and which is configured to discharge part of the cooling air used to cool the DC-DC converter into the passenger compartment. The power supply unit is configured to cool the DC-DC converter using cooling air used to cool a battery.
Patent Literature 2 discloses an onboard battery cooling construction which eliminates a forced layout of pipe connecting a battery pack with a cooling fan and minimizes resistance in a flow path by disposing the battery pack in a mounting space defined near front seats and disposing the cooling fan in a mounting space defined near rear seats. The onboard battery cooling construction thus enables an efficient discharge of cooling air.
Patent Literature 3 discloses a battery pack mounting construction which branches a discharge passageway into passageways which extend along both sides of a center console from a rear lower side of the battery pack and which communicate with a center floor reinforcement frame placed transversely of a vehicle body on a floor panel of a vehicle. The battery pack mounting construction discharges the cooling air to an exterior portion of the vehicle body via the center floor reinforcement frame and thus suppresses uncomfortableness given to occupants by cooling air used to cool batteries in a battery pack by providing the discharge passageway.